Phase 3 construction began in May, 2014 and will complete in fall, 2015.

Phase 3 will include:

Blasting and placement of 2.5 million cubic yards of earth and rock to form the final alignment of the unfinished segment.

Construction of approximately 20 miles of horizontal drains to remove subsurface water that causes landslide activity.

Construction of rock buttresses to mitigate landslide effects

Construction of 415 ground anchors to mitigate landslide effects

Traffic remains planned for the new highway segment in 2016.

Learn about the contractor selected for Phase 3 construction in this news release.

The US 20 Project (US 20 PME:UPRR-Eddyville) will complete a new, 5.5 mile segment of US 20 in Lincoln County.

The project will replace a ten mile segment of old US 20 that has narrow lanes and hairpin curves, with a 5.5 mile segment that will be straighter, with wide shoulders and miles of passing lanes.

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Overview

This project was identified by the Oregon Transportation Commission as a project of statewide significance and has substantial local and regional support.

The project is currently about half completed.1.7 miles of the new roadway is paved from the easterly end of the project into the Eddy ‘C’ Creek area.

1.13 miles is paved from the westerly end of the new alignment into the Cougar Creek area.

The remaining construction focuses on a 2.7 mile stretch in the center of the project where culverts will be constructed at four drainages where bridges had been previously planned.

The Challenges

Like most of the Coast Range, the project’s remote location is a combination of high, steep slopes, deep valleys and known landslide activity.

With more than 100-inches of annual rainfall common in the Coast Range, erosion control is a critical issue.

The heavy winter rains also affect the project’s operation.While the project length is described in years, in reality it is days, with only 85-days of earth moving in a construction year.

Because the new road slices straight through the Coast Range rather than following the curves of the valley, a lot of earth must be moved to create an even and consistent road grade.

The tops of hills are cut-off. That material is then used to fill the low lying areas.These so-called “cuts and fills” represent a significant part of the project.

The Landslides

From the early days of construction of the project, landslides in the four drainages at the center of the project have created construction challenges resulting in delays, work stoppages and millions of dollars worth of additional engineering and landslide mitigation construction.Much of that mitigation effort failed to stop the landslide activity; and where bridges were once planned over the four creeks, culverts will now be built, instead.

The Solution

ODOT is engineering a design to complete the project by taking an observational approach to data that is being collected . The effort is focusing on monitoring and reducing-or mitigating- the landslide activity, and replacing four planned bridges with culverts that the final highway will cross.

To learn how bridge components originally planned for this project will be reused on other projects,

The first step of the ODOT project is to relieve ground water pressure; then study exactly where and precisely what additional slide mitigation construction is needed; construct culverts to replace bridges at four creeks; and lower and realign parts of the roadway.We plan to have traffic on the new roadway in 2016.

Until then, we will construct the project in phases, allowing smaller contractors the opportunity to bid on each phase, rather than create a project that is so large, only national or international contractors could build it.

Phase 1 Construction: 2012-2013

With engineering advice and direction from Cornforth Consultants, Inc. , ODOT’s first priority after taking control of the project in June, 2012 was to drill horizontal drains to relieve groundwater pressure in the engineered fills, the cut hillsides, and natural landscape along the project.

These drains were designed to take groundwater away from the fills, cut slopes and hillsides.Groundwater pressure acts like a trigger for landslide activity.By reducing the amount of groundwater, we reduce the effects of the landslides.

In all, nearly 55 miles of horizontal drains were constructed in Phase 1.

Blanket drains, built with fabric and tons of crushed aggregate, were also constructed.These drains carry storm water and the drained groundwater into the nearby creeks and away from the hillsides and fills that will later be near or on the site of the roadway.

The first phase of construction also saw the demolition of four bridges and added hundreds of ground monitoring instruments that will help us evaluate the success of the mitigation efforts and help provide data for use to complete the project.

Phase 2-A Construction: 2013

Phase 2-A construction is now complete. Phase 2-A was a major safety project to realign a sharp curve east of Eddyville and improve safety along a nine mile stretch of current US 20 between Simpson Creek Bridge (MP 15.24) and Deer Creek Road (MP 24.25). Phase 2-A construction got underway July 30, 2013. To learn what safety improvements will be constructed, click here.

Later Phases

Additional phases of construction will include:

Phase 3 (2014-2015) will move 2 to 3 million yards of soil and rock to create the new final alignment; place fill over the culvert pipes; and install landslide mitigation

Phase 4 (2016) will include final roadway base construction and paving; a wildlife crossing; landscaping; and any needed final landslide mitigation

Phase 5 (2015) will improve habitat for fish, birds and other wildlife in up to nine areas on and near the project site.

The total estimated cost of the project is $365.7 million.

The entire project is on-schedule to put traffic on the new highway segment in fall of 2016.

2012-2013

2013

2014- 2015

2016

2015- 2016

2013-2015

Phase 1

Phase 2

Phase 3

Phase 4

Phase 5

Phase 6

Drainage- Horizontal & Blanket

Bridge Demolition

Cut 6 Slide Repair

Rock Production

Ground Anchor Testing Program

Permanent Pipes

Test Fills

Drainage: Horizontal & Blanket

Phase 2A: Existing Alignment Safety Improvements

Major Earthwork

Landslide Mitigation

Rockfall Mitigation

Cut 7 Ground Anchors

Roadside Development

Grading & Paving

Elk Passage

Signs & Striping

Continuing Landslide & Rockfall Mitigation

Environmental Mitigation

Floodplain restoration/creation near Little Elk Creek

Floodplain restoration/creation near Yaquina Meadows

On-site plantings

Fish Passage Mitigation

Protective Right of Way Purchase

Conservation Easements

Removal of fish barriers in Yaquina Bay Estuary

Additional Facts

About 460,000 feet of horizontal drains have been drilled.That’s nearly 90 miles of horizontal drain.

During a two-day, eight-inch rain event in November, 2012, the horizontal drains produced more than 2 million gallons of water per day.That’s equivalent to the daily needs of nearly 7,000 average Oregon households.

191,495 tons of rock has been produced. That’s nearly equivalent to the weight of two Aircraft Carriers.

4.3 million cubic yards of earth had been excavated, placed and compacted by February 2010.By 2016, the total will be 7.3 million cubic yards.That’s enough to fill more than eight Reeser Stadiums to the bleachers.

The area can receive more than 90 inches of rainfall each year.That means a narrow window of time for earth moving.The construction season is only 3 – 4 months for earth moving.

385 total borings. 107 “new” borings have been made since December 2011 for ground movement instrumentation.

One completed bridge and three partially completed bridges have been demolished.

Nine vertical and inclined ground anchors were installed and tested between November, 2012 and January 30,2013.

There are nine cuts in the project, one as deep as 260 feet.

There are 15 fills in the project, one as high as 180 feet.

Benefits

Safety - This route is a vital transportation link shared by commercial, recreational, and passenger traffic connecting the mid-coast with the Willamette Valley.This section of highway currently has a Safety Corridor designation put in effect when the corridor had a crash rate 60% higher than similar state highways.The project will make major safety improvements by building wider travel lanes and paved safety shoulders, providing a separated railroad crossing, and providing greater passing opportunities.

Economics - By opening the corridor to most interstate trucks, it allows a major employer in Toledo, Georgia Pacific, a more direct route to the Willamette Valley and the I-5 corridor.Currently more than 100 truck trips per day must travel out of direction north on US 101 through Lincoln City and use the OR18/22 corridor through Salem to access I-5.Additionally, opening the corridor to freight movement provides future opportunities for regional economic development.

Transportation system efficiencies – This project enhances regional connectivity by improving freight mobility on a major coastal feeder route.By providing more direct access for freight movement there are benefits to safety, congestion, and the environment.It will compliment the OR18/22 route and provide alternate routes for both the trucking industry and tourist traffic.It also provides for improved emergency access for the mid-coast region.